Rocker arm and cam assembly for internal-combustion engines



June 5, 1928. 1,671,973

R. T. ANDERSON ROCKER ARM AND CAM ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Original Filed April 10. 1926 a Z /a z/ w. MINI I" E 5 ll INVENTOR.

In] i 22 A TTORNE Y.

Patented June 5, 11928 1 U IT D;- STA.

BUSSELLT; ANDERSGN, OF'DENVEH, GDBOBADQ' ROCKER ARM AND CAM ASSEMBLY EOK IMIIINAL-OQKMSIION-ENGINEE a ease... filed April. 10, 1926, Serial No; mama. .ltenewedrJul-y 5., 192,7.

tion engine, andhas for its principal object, the PIO-VJSJQH oi: a device of this characterv which. will positively open and close the valves without spring operation, and in.

' which the action o'f the cam may be either multiplied or diminished-T uponthe action. of the valve. I

Another object is to provide a device of this. character which can be. operated from a cam shaft over the cylinderheadsso as to. eliminate push. rods, etc.

A further object is to arrange the device so that it will. be practically frictionless and so that itmay beadijusted' toiaccommodate wear Other objects and'advantages reside inthe detail construction of the invention, which is designed" for simplicity, economy, and efliciency.- These willbecome more, apparent from the ifoll'o'wing description. 1

In the following detailel description or the invention reference is had to the accompanying drawing which forms a part hereof; Like numerals refer to like parts in.

all', views ofthe drawing, and throughout the description.

Inthe drawing: r

' Fig.1 isa ve'rtical section through an in ternahcombustion engine cylinder illustrating the device in use. 3

Fig.2 i's'a plan View of the improved valve operating mechanism.

"Fig 3 is anenlarged vertical cross section through the rocker arm, taken at the center line oii'the'cam 'shat't, il'lustrating the roller construction.

Fig. l is a detail view of an alternate arrangement of the rocker arm.

Fig. 5 is a detail view of the upper extremity of the valve stem. I

In the drawing, the various partsof an internal combustion engine are designated as follows: cylinder 10, cylinder head 11, piston 12, water jacket 13, intake or exhaust passage 14, valve 15, valve stem 16, and valve stem guide 17.

My improved valve operating mechanism is installed upon or above the cylinder head 11 and comprises a cam shaft 18 supported on suitable brackets 19. The cam shaft 18 runs longitudinally of a series of cylinders 10 and carries adjacent each of the valve stems 16 in the series, an opening cam 20 and a closing cam 21.

the valve sten116.

39 arrangedflto slide upon the it away therefrom.

The cams 26 and .21Iareadjacent. but separated on the camshaitf18 andbetween them.

carriedv on supporting brackets 31, and. is,

spaced. from and surrounds, the cam shaft 18... The. arm extremity arranged to operate the valve 15; The yoke 23 rides in, a. spool 27 threaded on The spool .27 is locked in place on the valve 'stemby means of a lock nut, 28. threaded on the upper extremity thereof! The lock nut 28, compresses a washer 41.0 against the upper end of" the. spool'2fifj flat, conical spring, 29, is compressed between the washer 40" and a washer spool 27 and constantly clamp the yoke 23' between the spool flange and the washer39g I Upon one side of'the rocker arm 22, below the cam shaft 18, a roller 24 is carriedona short" roller] shaft" 25. Similarly carried, above the cam shaft I8'upon the rocker arm 22, is. a similar roller 26f. The rollers 24 and 26 constantly contact with the opening andTclosi-ng cams 20 and 21', respectively.

In operation, the rotation of the cam shaft 18" will oscillate the rocker arm 22 about its pivot 30, thus causing the yoke 23 toalternatelyraise the valve-15 to its seat-and force The spring 29 allows the rocker arm 22 to continue. its stroke for a shortgdistance after the valve'15 hasseated', and allows for expansion in the valve stem and any carbon or other foreign materialwhich may become lodged between the valve and its seat, thus preventing a rigid impact at the closing of the valve which might result in damage to the valve or valve mechanism.

To provide for adjustment betweenv the rollers and the cam, I place the roller 26 upon a bearing 32 which is eccentrically carried on a stud 33 in the rocker arm 22. The stud 33 is slotted at 35 to allow expansion.

of a screw driver in the slot 35, to bring the roller 26t0 or. from its cam 21. When the proper adjustment has been obtained the stud 33 may be locked in place by means of a set screw 34 threaded into its center,

which expands the stud in its seat in the rocker arm 22. I

It will be noted that the action upon the valve 15 isa multiplication of the cam action, owingto the fact that the yoke 23 is The stud can be rotated, by means 4 r A 1,671,913 ES. mrmr OFFICE- 22 carries a. yoke 23 at'it's one At the cam shaft the arm 37 is forked to support the rollers 2 1 and 26. In this form, the action of the cam shaft is reversed with reference to the action of the valve stem and if the distances between the valve stem 16, the pivot 36 and thecam shaft 18 are equal, the action at the two extremities will be equal. 7

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention. 7

Having thus described the invention, what I claim and desire secured by Letters Patent 1s:-

1. A valve operating mechanism comprisinga cam shaft; opening and closing cams carried by said cam shaft; a rocker arm pivoted at one side of said cam shaft and arranged to contact with said valve at its one extremity, said rocker arni arranged midway between said opening and closing cams; and oppositely extending projections on sa d arm arranged to engage said opening and closing cams, respectively.

'2. A valve operating mechanismcomprising a cam shaft; opening and closing cams carried bysaid cam shaft; a rocker arm pivoted at one side of said cam shaft and arranged to contact with said valve at its one extremity, said rocker arm arranged mid rocker arm pass above and below said cam shaft; rollers carried on said forked portions, each of said rollers engaging a different one of said cams; means for regulating the distance between said rollers, said means comprising a rotatable eccentric bearing for one of said rollers; and means for locking said bearing in any desired radial position.

at. A valve operating mechanism for internal combustion engines having a reciprocatmg valve; a pivot arranged adjacent said valve; a cam shaft arranged between said pivot and said valve; and a rocker arm eX- tending from said pivot to said valve, said cam shaft arranged to pass through said rocker arm. I

5. A valve operating mechanism for internal combustion engines having a reciprocating valve; a pivot arranged adjacent said valve; a cam shaftarranged between said pivot and said valve; a rocker arm extending from said pivot to said valve, said cam shaft arranged to pass through said rocker arm; an opening and closing cam carried on said cam shaft on opposite sides of said and oppositely placed,oppositely extending projections on said rocker arm, each adapted to engage a cam at one side of said rocker arm. i

In testimony whereof, I aflix my signature. v

RUSSELL r. ANDERSON. 

